The present invention relates to an apparatus and method of use for directly accessing the casing of a burning oil well preparatory to shutting off the flow therein. More particularly, the apparatus and method contemplate access to the casing directly adjacent the wellhead and near the ground surface.
In co-pending and commonly assigned application Ser. No. 697,398, filed May 9, 1991 and entitled "Directly Installed Shut-Off Valve Assembly For Flowing High Pressure Line", there is disclosed an apparatus for installing a reopenable shut-off valve in a flowing oil well casing. Also disclosed are a method for accessing the well casing below the surface of the ground by tunneling and for removing outer well casing layers to provide direct access to the oil production casing or pipe. The shut-off valve installation assembly disclosed in the above identified application may be applied and used on a well casing at virtually any point along its length. However, when the well is out of control and on fire, accessing the casing at some point substantially below the ground surface, by tunneling, protects the operation from heat and related hazards encountered at the wellhead. Nevertheless, tunneling methods are tedious, expensive and time consuming. Furthermore, the access tunnel becomes a more or less permanent installation without any substantial utility after the well has been brought under control and the fire extinguished.
Therefore, it would be desirable to have some other means for providing access to the well casing near the wellhead at the surface of the ground which would obviate tunneling. However, any such means would have to provide protection against the heat and related hazards of the burning wellhead. Also, it would be desirable to provide an apparatus which could be removed after the well has been brought under control and reused at other well sites.